This invention relates to a method and apparatus for sterilizing and detoxifying confined spaces using hydroxyl free radicals. In particular, it relates to exposing ozone and a hydrogen atom donor to ultraviolet light (UV) to generate hydroxyl free radicals, which kill microorganisms and degrade toxic chemicals inside an enclosure.
The recent dissemination of anthrax through the mails has created a need to sterilize mail rooms and offices. For example, anthrax found in the Senate Office Building was killed using chlorine dioxide, a highly toxic gas, followed by sulfite to destroy the chlorine dioxide. However, chlorine dioxide can react with organic compounds to form chlorinated organic compounds that remain in the room and may be carcinogenic. Moreover, the disinfection was not successful and liquid bleach had to be used to remove the last traces of anthrax and anthrax spores. Thus, chlorine dioxide is not entirely satisfactory for this purpose.
Ozone has also been used to sterilize enclosed spaces. When microorganisms are exposed to ozone, the ozone passes into the organisms, attacking their DNA, and killing them. Unlike chlorine dioxide, ozone forms oxygen a few hours after it is used and is not known to form carcinogenic organic compounds unless the organic compound is chlorinated. While ozone is a potent oxidant, in sufficiently high concentrations it may be dangerous to human life.
The presence of toxic chemicals, such as a nerve gas, in buildings or other enclosed spaces is also a concern and substances that are effective against pathogens may not degrade chemical warfare agents.